$ sudo cpan -i "Heap::Simple"
CPAN: Storable loaded ok (v2.20)
Going to read '/home/bchenlab/.cpan/Metadata'
  Database was generated on Fri, 27 May 2011 17:27:32 GMT
Running install for module 'Heap::Simple'
CPAN: Data::Dumper loaded ok (v2.124)
'YAML' not installed, falling back to Data::Dumper and Storable to read prefs '/home/bchenlab/.cpan/prefs'
Running make for T/TH/THOSPEL/Heap-Simple-0.13.tar.gz
CPAN: Digest::SHA loaded ok (v5.47)
CPAN: Compress::Zlib loaded ok (v2.02)
Checksum for /home/bchenlab/.cpan/sources/authors/id/T/TH/THOSPEL/Heap-Simple-0.13.tar.gz ok
CPAN: Archive::Tar loaded ok (v1.52)
Heap-Simple-0.13/
Heap-Simple-0.13/Makefile.PL
Heap-Simple-0.13/Changes
Heap-Simple-0.13/README
Heap-Simple-0.13/t/
Heap-Simple-0.13/t/Heap-Simple.t
Heap-Simple-0.13/MANIFEST.SKIP
Heap-Simple-0.13/MANIFEST
Heap-Simple-0.13/META.yml
Heap-Simple-0.13/lib/
Heap-Simple-0.13/lib/Heap/
Heap-Simple-0.13/lib/Heap/Simple.pm
Heap-Simple-0.13/lib/Heap/Simple/
Heap-Simple-0.13/lib/Heap/Simple/Package.pm
Heap-Simple-0.13/md5-versions
CPAN: File::Temp loaded ok (v0.22)

  CPAN.pm: Going to build T/TH/THOSPEL/Heap-Simple-0.13.tar.gz


You seem to have neither 'Heap::Simple::XS' nor 'Heap::Simple::Perl' installed.
That should not stop this package from getting installed (in fact, you'll need
to install this package before you can install any of the other two).
However, this package won't be usable until you install one (or both) of these
two.

Checking if your kit is complete...
Looks good
Writing Makefile for Heap::Simple
Could not read '/home/bchenlab/.cpan/build/Heap-Simple-0.13-ixBMb5/META.yml'. Falling back to other methods to determine prerequisites
  THOSPEL/Heap-Simple-0.13.tar.gz
  make -- NOT OK
Warning (usually harmless): 'YAML' not installed, will not store persistent state
Running make test
  Can't test without successful make
Running make install
  Make had returned bad status, install seems impossible